597: Ja'mmaa'a Prayer with a man and a woman
only

Can a muslim one man and one woman perform
janaat together?

Yes, it is permissible for one man to pray jamaa'ah (in
congregation) with one woman (say his wife). She would
stand behind him. (Note from the translator: It should be
understood that this would not substitute the man praying
jamaa'ah in the mosque whenever applicable.)